Box car door safety latch



16, 1955 J. H. SPENCE BOX CAR DOOR SAFETY LATCH Filed Aug. 22, 1951United States Patent @fitice 2,715,539 Patented Aug. 16, 1955 BOX CARnoon SAFETY LATCH John H. Spence, Chicago, 111., assignor toPullman-Standard Car Manufacturing Company, Chicago, 111., a corporationof Delaware Application August 22, 1951, Serial No. 243,014

2 Claims. (Cl. 292-189) The present invention relates to a lock forsliding box car doors or the like, and more particularly to safety latchmeans for such doors.

In the embodiment of the invention disclosed herein, a latch member isslida'oiy mounted in brackets extending outwardly from a box car slidingdoor, normally projecting downwardly below the lower edge of the doorfor engagement with one or the other of a pair of keepers fixedlymounted on the car adjacent the door. The keepers have cam surfaces bywhich the latch member is raised so as to ride over the keeper when thedoor is moved to one position, and a relatively abrupt abutment facewith which the latch member engages as it drops back to the normalprojecting position after riding ofi the cam surface. Return movement ofthe door is thus prevented until the latch member is intentionallyraised out of engagement with the abutment face of the keeper. Front andrear stop members are provided for the door, the front one of which isthat commonly employed at the forward end of a box car opening closed bythe door, and the keepers are so located relative to the stop membersthat the door is held against substantial movement in either directionwhen disposed in its closed or open positions. The latch member,brackets, keepers, and rear stop member are all formed of flat sheet orplate material of suitable characteristics, preferably steel, and thelatch member particularly is in the form of a flat, straight strip ofthe material and carried parallel to the door so that it engagesedgewise with the keepers and all stresses imposed on it in holding thedoor against movement act in its single plane. The possibility ofshearing off or breaking of the latch member, whichmight occur throughtorsional strain if the latch member were of offset formation so as toextend in more than one plane, is minimized and in fact practicallyeliminated. In addition, the latch and other parts may be formed by asimple, rapid operation such as stamping, instead of by casting orforging as would be necessary otherwise, so that the cost of manufactureis greatly reduced. The latch is formed with integral lugs on theportion thereof extending between the brackets so that its movement ineither direction is limited and it is held against disengagement withthe brackets. The thickness, width, and shape of this portion of thelatch are such that it provides a hand grip which may readily be graspedfor release from latching engagement with a keeper, and the latch isheld appreciably spaced from the door by the brackets, so that a handmay easily close around it. Thus no operating levers or other membersare required to move the latch manually, and the construction is made assimple as is possible.

The advantages pointed outcheapness of manufacture, resistance tobreakage, simplicity of construction, and ease of operationare veryimportant in practice, particularly in the case of railroad cars,because of the reduction of cost, elirnination of repairs, reduction ofweight, and increased safety.

It is therefore an important object of the invention to provide safetylatch means for sliding doors such as employed on box bars which has itsparts formed of sheet or plate material by simple operations.

Another object is the provision of safety latch means for sliding doorsincluding a latch member of fiat, straight construction extending in asingle plane and so disposed that the stresses imposed thereon act onlyin that plane, to obtain maximum stress distribution and resistance toshocks and minimize breakage.

Another object is the provision of safety latch means for sliding doorsin which a slidable latch is mounted on the door in spaced relationthereto and has a portion in the same plane as the remainder thereof ofsuch shape and transverse dimensions as to provide a hand grip by whichit may readily be grasped.

It is another object to provide safety latch means for sliding box cardoors and the like of the simplest possible construction.

It is also an object of the invention to provide safety latch means forsliding doors which are easily and cheaply manufactured and applied tothe doors.

Other and further objects, advantages, and features of the inventionwill be apparent to those skilled in the art from the followingdescription in conjunction with the accompanying drawing, in which:

Fig. l is a fragmentary side elevation of a box car and sliding doortherefor showing the safety latch applied thereto;

Fig. 2 is an enlarged vertical sectional view taken substantially asindicated by the line 22 of Fig. 1;

Fig. 3 is an enlarged perspective view of the latch and its brackets;and

Fig. 4 is an enlarged perspective view of one of the keepers.

Referring to Fig. l of the drawing, safety latch 10 is shown as appliedto the sliding door 11 of a box car 12 having the usual sub-side sill 13and front door stop member 14 at the forward edge of the car dooropening. Door locking and sealing means 15 of known construction may beprovided. The door 11 is shown as made of steel and of the bottom hungtype, having rollers 16 adjacent its outer face disposed in housings 17.Brackets 18 extending from the sub-sill 13 support a horizontal track 19for the rollers 16 which extends rearwardly from the front stop member14. A flange 29 depends from the outer edge of thetrack 19, the trackand flange preferably being provided by an angle member. A rear doorstop member 21 is welded or otherwise secured on the rear portion of thetrack 19, at a point to be engaged by the rear edge of the door when itis fully opened. The stop member 21 may conveniently be formed of astrip of steel.

A latch 22 in the form of a fiat, straight strip of steel or the like issupported vertically on the door by horizontally disposed brackets 23spaced vertically to each other and projecting outwardly from the doorand having suitable slots through which the latch extends in slidablerelation. In the present instance, the brackets are shown as simple flatlugs of steel or the like having one edge welded to the door 11. Thebrackets hold the latch parallel to and spaced appreciably from thedoor, as best shown in Figs. 2 and 3, so that it may project downwardlybelow the lower bracket alongside the flange 20 of the track 19. Theside edges of the latch 22 are formed with projections or stop lugs 24at points inwardly of the upper and lower ends thereof. The upper andlower lugs are spaced apart a distance less than the spacing of thebrackets and are disposed between the brackets to abut thereagainst forlimiting the sliding movement of the latch in the brackets. In itsnormal or latching position, the latch has its lower end extending belowthe track 19 and alongside the flange 20, the lower lugs resting on thelower bracket 23. Between the upper and lower lugs 24, the side edges ofthe latch have portions 25 curved inwardly toward each other so that theperimeter at the central portion of the latch 22 is such as to be easilygrasped and encircled by the hand, and wider portions are providedadjacent the stop lugs to prevent the hand from slipping along thelatch. A hand grip is thus formed by the central latch portion tofacilitate manipulation of the latch. The spacing of the latch from thedoor allows the fingers to pass freely therebetween.

A pair of keepers 27 are secured on the outer face of the flange 2% inposition to be engaged by the latch in its normal position. Each keeperis formed of a steel strip bent to provide a vertical abutment portion28, having its upper edge joined by a horizontal portion 2? to the upperedge of an angled cam portion 39. Each keeper is welded by one side edgeto the flange 24 one keeper being located at a point on the flange toengage the latch 22 in the closed position of door 11 with its abutmentportion 23 facing forwardly, and the other being reversely arranged at apoint on the flange to en age the latch in the open position of the doorwith its ab tr ent portion facing rearwardly. The forward keep-2. isspaced rearwardly of the front stop member 14- distance corresponding tothe spacing of the latch 22 from the forward edge of the door, While therear keeper is spaced forwardly from the rear stop member 2i a distancecorresponding to the distance of the latch from the rear edge of thedoor.

In the closed position of the door 13, as shown in Fig. 1, the latch 22is disposed in latching position just forwardly of the abutment portionof the forward keeper 27, against which it abuts upon attempted rearwardmovement of the door to prevent such movement. Since the forward edge ofthe door in this position engages the front stop member 14, the door isprevented from moving in either direction, except that the parts may bearranged to permit some clearance if desired. To open the door, assumingthe locking means 15 have been released, the latch 22 is grasped by thehand grip constituted by the central portion thereof and is lifted so asto clear the abutment portion of the keeper, and the door is movedrearwardly. The latch may be released to ride over the horizontal keeperportion 29 and down the cam portion 30, if desired. As the doorapproaches fully open position, the latch in its normal position engagesthe cam portion of the rear keeper and is raised thereby so as to rideover the keeper until it passes the abutment portion, when it drops tothe normal latching position to prevent forward movement of the door. Asthe latch passes to the rear of the keeper, the rear edge of the doorcomes into engagement with the rear stop member 21, so that the door inits open position is held against any substantial movement in eitherdirection. To close the door, the latch 22 is again manually lifted andthe door is rolled forwardly, the latch passing over and dropping intolatching relation with the forward keeper in the manner described inconnection with the rear keeper.

Since all the shocks and stresses of any moment imposed on the latch 22arise from its movement in a plane parallel to the door, thestraight-line or single-plane formation of the latch 22 and itsdisposition parallel to the door and edgewise to the keepers providesfor the best possible reception and absorption of impact shocks, thestrains being imposed on the latch in only one plane and having notorsional effect. Thelatch, brackets, keepers, and rear stop member maybe stamped or punched from sheet or plate of steel in a simple,expeditious, and inexpensive operation, the latch and brackets being soformed in substantially their final forms and the keepers and rear stopmember requiring in addition only a simple bending operation. The latchwithout any but its single forming operation is adapted to serve as itsown handle, and requires additional members or means for itsmanipulation. It will therefore be clear that a very simple,inexpensive, and easily formed latch means has been provided, yetonewhich affords optimum stress distribution and consequent resistanceto shock and breakage in use.

What i claim is:

l. Latching means for a door slidable along a vertical wall to open adclose an aperture therein, comprising a pair of ye" spaced ilat bracketplates extending horizontally fro e door each having a closed elongatedslot therein extending substantially parallel to the door, said slotsbeing located in vertically registering relation, and

a flat plate-like latching element slidably engaged for verticalmovement in said slots of said bracket plates and mounted thereby inspaced substantially parallel relation to the door, said latch elementhaving upper and lower end portions of a width corresponding to thelength or the slots in the respective upper and lower bracket plates andportions of greater width adjacent the end portions vertically spaced adistance less than the spacing of said bracket plates and respectivelyengageable with the adjacent of said plates to limit sliding movement ofthe latch element in opposite direction, said latch element also havinga portion between said wider portions defined by inwardly curving sideedges and providing a hand grip for ready grasping in raising of saidelement and moving of the door.

2. Latching means for a door slidable along a vertical wall to open andclose an aperture therein, comprising a pair of vertically spacedbracket members extending from the door each having a closed elongatedslot defined therein extending substantially parallel to the door, saidslots being located in vertically registering relation, a flat platelikelatching element engaged for vertical sliding movement in said slots ofthe bracket members and located thereby in spaced substantially parallelrelation to the door, said latch element having upper and lower endportions of a width corresponding to the length of the slots in therespective upper and lower bracket members and vertically spacedportions of greater width adjacent the end portions respectivelyengageable with the adjacent bracket members to limit sliding movementof the latch element in opposite directions, said latch element alsohaving the portion thereof between said wider portions narrowed forready grasping in raising of said latch element and moving of the door.

References tilted in the file of this patent UNITED STATES PATENTS863,285 Kendig Aug. 13, 1907 1,487,667 Ornler Mar. 18, 1924 2,106,166Busse Jan. 25, 1938 2,167,707 Busse Aug. 1, 1939 2,516,210 Hess July 25,1950

